Heat exchanger



Sept. 23, 1952 c. BOLING HEAT EXCHANGER Filed March 30, 1948 INVENTORPatented Sept. 23, 1952 HEAT EXCHANGER Cecil Boling, Brewster, N. Y.,assignor to-The Heat-X-Changer. 00., Inc., Brewster, N. Y., acorporation of New York Application March 30, 1948, Serial No. 17,899

8 Claims. (Cl. 257241) This invention relates to the transfer of heatfrom one fluid to another, and more in particular to highly efficientheat-exchange units and the method of makingthe same.

An object of this invention is to provide a heat exchange assemblywhereby heat is transferred from one material to another in an extremelyheat-exchange units of the above character in a.

simple manner which is inexpensive and yet thoroughly practical in everyrespect. These and other objects will be in part obvious and in partpointed out below.

The invention accordingly consists in the features of construction,combinations of elements, arrangements of parts and in the several stepsand relation andorder of each of the same to one or more of the others,all as will be illustratively described herein, and the scope of theapplication of which will'be indicated in the fol:- lowing claims. y

In the drawing: r Figure 1 is a side plan view with portions broken awayof a heat-exchange unit constituting one embodiment of the invention;

Figure 2 is an enlarged sectional view on the line 2-2 of Figure 1'; 1 A

Figure 3 is an enlarged sectional view on the line 3--3 of Figure 1showing only the central portion of the unit; and,

Figure 4 is a top plan view. of the unit of Fig- 4O urel. v.

Referring to Figure 1 of the drawing, an elongated cylinder or tube 2has coiled about it a spiral tube 4 which formsfive complete'turnsbetweenits flareden'ds 6' and 8. .The ends of tube2 are reducedat land"l2,,and except for these reduced ends, substantially the entire tube2 and substantially the entire length of tube 4 are embedded in a castaluminum block-l4; block I4 is cylindrical with two protrusions I6 and18 at the ends surrounding theportions of tube'4' ad- A further 0b-""jac'ent ends 6 and B. "As shown best in Figure 2.

tube 4 is somewhat ovalin-*cross-section-,- having been originallycircular in cross-section, and; hen having been deformedto the ovalshape when wound into aspiral: r

Positioned within tube 2 is a heat-exchange assembly 20 which is formedby a central expanded tube 22 and a fin construction 24. The structureof fin construction 24 is best shown in Figure 3 where it is seen thatit is formed from a corrugated sheet of metal bent into cylindricalform. There are 21 flat fin portions or corrugations, and thecorrugations originally forming the edges of the sheet are-overlapped toform a single fin portion so that there are ten pairs of fiat finportions symmetrically positioned in the annular space between tubes 2and 22. Each of these flat fin portions is positioned substantiallyradially with respect to tubes 2 and 22, and in this form they extendtangentially with respect to an imaginary cylinder the diameter of whichis approximately one-half the diameter of tube 22.

During manufacture, tube 2 originally has its ends of the same diameteras its main body portion and tube 22 is of slightly smaller diameterthan here appears; thus, fin construction 24 and tube 22 are readilypositioned within tube 2. The two tubes and the fin construction thenare held fixed and tube 22 is expanded to the diameter shown. Thisexpanding is performed by drawing through the tube a cylindrical die ofgreater diameter than the original internal diameter of tube 22. Thus,tube 22 is expanded so that it continually presses outwardly againsteach fin portion, and expands the fin construction 24 with considerableforce against the inner surface of tube 2. In this way an extremelyrigid heat transfer assembly is provided within tube 2, and each of thefin portions is in good heat contacting relationship with tube 2 as wellas with tube 22.

After the expanding of tube 22 the ends of tube 2 are reduced and tube4, which has-been wound into a spiral in a mandril, is slippedintoplace. The tube assembly thus formed is then positioned within amold andthe block of aluminumis cast around it. The aluminumbonds to the entireembedded surfaces of tubes 2 and 4 and provides excellent heat transferrelationship between the aluminum and each of these tubes. As shown bestin Figure 3, tube 4 is in intimate contact a with tube 2 and thealuminum fills into the cracks at the edges of tube 4 sufficiently toavoid any cavity. Block [4 not only provides for the even distributionand transfer of heat between tube '2 and tube'4, but the blockalsoprovides; a heat carry-over so that fluid is cooled evenly in one tubeand heated evenly in another. tube without minor fluctuations intemperature in the one is a tendency for the entirewall of tube 2 tubemaintained at substantially the same tempera-- ture.

The gas passing through tube 2 is-carried in assembly within saidannular chamber and comprising sheet metal corrugations each of which issubstantially straight and is non-distortable and extends longitudinallyof said chamber bridging the space between said rigid members and isconnected to the next adjacent corrugation by a trough-like connectingportion-whichpresents a straight portion-in contact with a surface ofone of said members, the distance between said rigid cylindrical membersbeing such that each of said trough-like connecting portions isdistorted and each of said trough-like connecting portions issubjected-to substantial compressive forces which I tare applied at theinner and outer peripheries of the passageways between the fins of finconstrue tion 24 as well as through tube 22, and'there'is" a minimumresistance to flow. Some of the heat from tube 2 is picked up directlyby the refrigerant gas, but the major portion of the heat passes byconduction from tube 2 to the various fin portionswith this heattransfer being facilitated'by the excellent contact which is providedbetweenttube' 2 and the corrugation ridgesor fin edges. An additionalamount of heat passes from the fin portionsto the gas while theremainder-of: theyheat is transferred from the fin to tube22 and thenceto the gas around and mainly withinthistube. I n

In this embodiment-tubes}, 4- and 22 and fin construction 24 are, ofcopper and the passageways for the refrigerant arefree of othermaterials such as solder andpthe like. to be. of: advantage in theadaptation of this invention to certain "uses. 7 r

As many possible embodiments may bemade of the mechanical features ofthe above invention This has proved and as the art" hereindescribedmight be varied in variousparts; allwithoutdeparting from the scope ofthe invention; itzis'to be understood that all matter hereina-bove setforth, or shown in the accompanying drawings is to be interpreted asillustrative and not ina limiting sense.

Iclaim: 1

V 1". In: heat exchange: apparatus of: the type whereina fiuid'i'ssubjected'to a heatv transfer operation, the combina tion of, a pair ofconcentrically positioned rig-idmembers; defining a substantiallyannular chamber for the flow-of the fluid to be subjectedfto aheat'transfer operation, and anannular'rnetallic fin assembly withinsaid chamber and comprising sheet metal corrugations each of whichissubstantially straight and .tion which presentsastraight portionincontact V wima surface of one-of said membera the distance betweensaid rigid members :b 'eing. such that each ofsaid trough-like:connecting portions is distorted and-each of saidtroughelike connectingportions issubj'ectedcto substantial compressive forces which areapplied at the inner and: outer peripheries of said fin assembly bysaid. rigid members. 7

H -2. In heat exchangelapparatus of the; type wherein" a fluid, issubjected to aheat transfer operation, the'zcombination of, a .pair ofhollow concentrically positioned rigid cylindrical .mem-

bers defininga; cylindrical central chamber; and

an annular chamber. both of which chambers are transfer operation, andan annular metallic fin for the flowof :flu-id-to. be" subjected to ,ahea-t said fin assembly by said rigid members.

wherein 'a' fl'uidis subjected to a heat transfer operation, thecombination of, a pair of concentrically positioned rigid cylindricalmembers defining-a substantially annular chamber between the-cutersurface ofthe smaller of said members and the inner surface of thelarger of said members, saidmembers providing for the flow throughsaidannular chamber of thefluid to be subjected to a heat transfer.operation, an annular metallic finassembly within said chamber andcomprising sheet metal corrugations each of which is substantiallyrectangular and straight and is not distorted and extends longitudinallyof said chamber bridging the space between said rigid members andisconnected to the next adjacent oorrugation by a trough-like connectingportion Which3presents a straight portion'in contact with atsurface ofone of said cylindrical members,

being such thatreach .of said trough-like connecting portions is,distortedand each of said trough-like connecting portions 'is subjected,to substantial compressive'forces-which are applied at-the inner andouter peripheries of said fin assembly by said cylindrical members, andmeans exteriorly of the larger of sai'dcylindrical .members andproviding a' passageway-fora second fluid and providing for the transferof heat between fluid fl'oWing-through' said cylindrical members andsaid secondfluid. 1

4. Inheat exchange apparatus of the type wherein a fluid is subjected toa heat transfer operation, the combination of, a pair ofconcentricallypositioned hollow rigid cylindrical members defining a substantiallyannular chamber between the outersurface of the smaller of said membersand the inner surface of the larger of said members and a cylindricalpassageway within the smaller of said memberssaid members providing forthe flow through said annular chamber and said" cylindrical passagewayof fluid to be subjected to'a heat transferoperation, an annularmetallic fin assembly within said chamber and comprising sheet metalcorruga= tio'ns. each of which isfsubstantially rectangular and straightand is j bt j distorted and extends longitudinally ofsaid'charfiberbridging the space between 'said rigid'inember's and is connected tojithe nextadjacentcorrugation :bya trough like;v connecting portion whichresents a straight portion in contactwith a surface ofone of saidcylindrical iifeirlbers, the distance between said cylindrical membersbeing such that each of said trough dike connecting: portions isdistorted and each of said tro'ugh like connecting portions, issubjected =tosubstantial compressive forces which are applied atf theinner" anapu er peripheries of said fin assemblyby s ai d'cylind'ri calmembers, and heat transfer means" in intimate contact with the outersurface of the larger of said cylindrical members and providing a.passageway for a second fluid and providing for the transfer of heatbetween fluid flowing through said cylindrical members and said secondfluid.

5. In heat exchange apparatus of the type wherein a fluid is subjectedto a heat transfer operation, the combination of, a pair ofconcentrically positioned rigid members defining a substantially annularchamber for the fiow of the fluid to be subjected to a. heat transferoperation, an annular metallic fin assembly within said chamber andcomprising sheet metal corrugations each of which is substantiallystraight and is non-distortable and extends longitudinally of saidchamber bridging the space between said rigid members and is connectedto the next adjacent corrugation by a trough-like connecting portionwhich presents a straight portion in contact with a surface of one ofsaid members, the distance between said rigid members being such thateach of said trough-like connecting portions is distorted and each ofsaid troughlike connecting portions is subjected to substantialcompressive forces which are applied at the inner and outer peripheriesof said fin assembly by said rigid members, a tube formed into a spiraland closely hugging the outer surface of the larger of said rigidmembers, and a block of aluminum substantially enclosing said largerrigid member and said tube.

6. Apparatus as described in claim 5 wherein said spiral tube issubstantially oval in crosssection, and wherein said fin assembly isformed by a single sheet of corrugated metal.

7. Apparatus as described in claim 6 wherein said rigid members aresheet metal cylinders and the larger of said cylinders has its endsreduced in diameter and projecting from said block of a uminium.-

8. In heat exchange apparatus of the type wherein a fluid is subjectedto a heat transfer operation, the combination of, a pair ofconcentrically positioned rigid members defining a substantially annularchamber for the flow of the fluid to be subjected to a heat transferoperation, and an annular metallic fin assembly within said chamber andcomprising a sheet of metal formed into corrugations each of which issubstantially rectangular and straight and is non-distortable andextends longitudinally of said chamber bridging the space between saidrigid members, each of said corrugations being connected to the nextadjacent corrugation by a trough-like connecting portion which presentsa straight portion in contact with a surface of one of said members, thedistance between said rigid members being such that each of saidtroughlike connecting portions is distorted from its original shape andeach of said trough-like connecting portions is subjected to substantialcompressive forces which are applied at the inner and outer peripheriesof said fin assembly by said rigid members.

CECIL BOLING.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 660,292 Durr Oct. 23, 19001,270,198 Parkhurst June 18, 1918 1,584,772 Hyde May. 18, 1926 2,004,389Jones June 11, 1935 2,206,826 Hopper July 2, 1940 2,324,395 Hoop July13, 1943

